SummaryToday the environmental goods and services are in demand. This affects trade and the way to do business. The demands of environmentally branded products have therefore increased. The standards, line systems and control systems have been taken a significant position. At this point the certification has been created.In our study we wanted to investigate if certification is the right tool to use for a company to promote sustainability or if certification is necessary for a company to survive on the market. This led us to contact a number of successful companies in sustainability.We interviewed the managers of the companies or sent questions via mail. We have been inspired of a methodology called Grounded Theory. This methodology focuses on significant meanings found in the empirical material. The key meanings will then be categorized in main categories, under categories and sub categories. We found that “certification” was the main category in the companies when sustainability was discussed. After that we created statements to existing theory.Companies in the study have a will to protect the environment but the major reason to certify was because of customer demands. Some claimed that the companies wouldn’t be able to survive on the market if certification wasn’t done. In a sense the situation resembles “the cat on the rat, the rat on the rope”. This indicates that company’s market value increases when they certify their businesses.Despite the demands of certification from customers and suppliers, companies are not willing to pay for the certification. The certification will therefore be the main issue and the company will not be compensated for it. Therefore the certification will be more like a tool of competition than an environmental protection for the company. Yet, we believe that the environmental will play a greater part in the future when the companies choose to certify themselves.